Inhibitory and Stimulatory Effects of Oregano on <i>Lactobacillus Plantarum</i> and <i>Pediococcus Cerevisiae</i>

Abstract

ABSTRACT Increasing concentrations of oregano from 0.5 to 8 g/L in a liquid medium resulted in stimulation, delay, or inhibition of acid production and viability of Lactobacillus plantarum and Pediococcus cerevisiae. The inhibitory factor could be removed from oregano by solvent extraction or autoclaving; residues from these treatments stimulated acid production by the organisms. Organisms growing in media containing sublethal oregano concentrations that had delayed growth and acid production developed resistance to the deleterious effects of the spice. L. plantarum was more resistant than P. cerevisiae to the inhibitory effects of oregano.